Yield Stability Analysis of Wheat Genotypes in Large Number of Environments Using Univariate Parametric Statistical Models

-Wheat is the most important crop of many countries including Pakistan. Assessment of Yield stability of wheat in different environments has been an important issue for wheat growers and horticulturists. In present paper yield stability of wheat genotypes is assessed at different research institutions/stations across the country using univariate parametric stability models and interrelationships among the stability statistics are evaluated. The yield data set is based on Multi Environment Trials evaluated by National Uniform Wheat Yield Trials (NUWYT) for 200405. Experiments were performed with 20 genotypes in 40 environments using individual randomized complete block design (RCBD). A unifactor and combined analysis of variance (ANOVA), stability statistics, and rank correlations among various stability statistics were performed. The results from combined ANOVA indicated that a highly significant ( ) GEI was accompanied by highly significant genotype and environment main effects. Most of the stability models (7 out of 12) did not identify stable and unstable genotypes in similar fashion. Three out of twelve stability statistics identified four genotypes G1, G20, G2 and G7 as the most stable and high yielding and three genotypes G11, G14 and G8 as unstable with low yielding performance. Further, mean yield of cultivars was significantly correlated with Hernandez’s Desirability Index (DIi ), Geometric Adaptability Index (GAIi, ), Kataoka’s Reliability Index (Ii, ), and Coefficient of Determination (Ri 2 ). The statistics DIi and GAIi may be alternatively used to select high yield and stability, whereas Ii and Ri 2 may alternatively be used for the selection of high yield cultivars.